Foot controller with interlock circuit

ABSTRACT

A foot controller  32  for use with ophthalmic surgical equipment  34  includes a foot controller  32  having a door  18.  Door  18  covers a surgical switch  24  when door  18  is in a closed position, and door  18  is a shroud for a surgical switch  24  when door  18  is in an open position. A door-position sensor  48  disables activation of the surgical switch  24 , except when the door is in an open position.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to foot controllers for use inophthalmic surgery.

[0003] 2. Description of the Prior Art

[0004] Foot controllers for ophthalmic and other types of surgery arewell-known. These foot controllers typically include an accelerator-typepedal that moves in both the vertical and horizontal directions. Themovement of the accelerator pedal controls various surgical instrumentsand settings of the surgical system, depending on the particularoperation being conducted. The foot pedal controls such things as howmuch power is supplied to a phacoemulsification handpiece or pneumaticscissors or vitreous cutter. In addition, such foot controllerstypically include one or more additional buttons which are activated bya user pressing his foot on the button. These buttons control stillfurther operations of the surgery equipment.

[0005] Certain surgery equipment requires a shroud to be formed aroundand above the switch to prevent accidental activation of the switch.Such equipment, for example, can be a surgical laser. Obviously, a userwould not wish to inadvertently fire a laser pulse, and therefore, theshroud is provided. Typically, in the prior art, such shrouded switcheshave been separate from the main foot controller in ophthalmic surgery.

[0006] It would be highly desirable to have a foot controller with anaccelerator-type pedal, such as known in the prior art, that combines afoot switch that requires a shroud. By this combination, another pieceof equipment on the floor can be eliminated and the user, typically asurgeon, will always know the exact switch location.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 illustrates a foot controller in accordance with thepresent invention with a door in a closed position;

[0008]FIG. 2 illustrates a foot controller of the present invention witha door in an open position;

[0009]FIG. 3 is an illustration of a ophthalmic surgical system inaccordance with the present invention; and

[0010]FIG. 4 is a block diagram of a switch interlock circuit inaccordance with one aspect of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0011]FIG. 1 shows a foot controller 10, in accordance with the presentinvention. Foot controller 10 includes a body portion 12, anaccelerator-type pedal 14, and control buttons 16. In use, footcontroller 10 is typically attached to an ophthalmic surgical system,such as the Millennium® system available from Bausch & Lomb Inc. (notshown). Foot controller 10 by use of accelerator-type pedal 14 orswitches 16 activates and controls various surgical instruments, as iswell-known. In addition to the pedal 14 and switches 16, the presentinvention incorporates a door 18 covering a switch 24 (shown below). Thedoor 18 functions as a heel-rest when in a closed position of FIG. 1,and as a switch-shroud when in an open position of FIG. 2. Preferably,door 18 includes a heel-rest ridge 20 for user comfort. In addition,door 18 preferably includes a toe-ridge 22 for allowing a surgeon toopen door 18 easily. However, it is noted that foot controller 10 mayhave one or more doors 18 covering switches 24 and/or 16. It is notnecessary that door 18 also be a heel-rest.

[0012]FIG. 2 shows foot controller 10 with door 18 in an open position.As can be seen, switch 24 controlling a surgical apparatus, such as alaser, is effectively shrouded by door 18, thereby preventing unintendedactivation of switch 24. Preferably door 18 is spring-loaded so that thedoor will automatically close unless in an open detented position.

[0013] In this way, a surgical switch 24 requiring a shroud isconveniently incorporated into an otherwise typical foot controller foruse in ophthalmic surgery.

[0014]FIG. 3 shows an ophthalmic surgical system 30 consisting of a footcontroller 32, a surgical console 34, and optionally, a satellite footswitch 36. Surgical console 34 may consist of a cart 38, a base orcontrol unit 40, and optionally, an expansion unit 42. Foot controller32 and switch 36, as indicated by dashed lines 44, may be connected toany one of units 38, 40, and 42. Optional satellite foot switch 36 isshown connected to surgical console 34 via a common node 46. It shouldbe appreciated that satellite foot switch 36 is generally dedicated toone surgical apparatus, such as a surgical laser and generally, isrequired to be shrouded as discussed above.

[0015] In practice, it may be desirable to have such a satellite switch36 for the convenience of the surgeon in that, as the surgeon movesabout the patient, switch 36 is more easily moved than main footcontroller 32. For the sake of safety, it may be desirable to have aninterlock or safety checks on foot controller 32 to ensure that switch24 is not activated by accident.

[0016] To ensure that switch 24 is not accidentally activated on footcontroller 32, it is desirable to have a door position sensor 48 fordisabling activation of the surgical switch 24 except when the door 18is in an open position. Door position sensor 48 may consist of a magnet50 in combination with a Hall-effect IC 52 to form a Hall-effect sensor.Then, when the magnet moves to a position adjacent Hall-effect IC 52,switch 24 is enabled. For situations in which redundancy is desired, adoor-presence sensor 54 for detecting when a door is present on a footcontroller may also be used. Like sensor 48, sensor 54 may consist of amagnet 56 on door 18 and a Hall-effect IC 58. In much the same way assensor 48 detects that the door is in a proper position, if sensor 54 isused, then the presence of door 18 must be detected before switch 24 isenabled. That is to say in such a redundant system, surgical switch 24is disabled except when the door is present and open as detected bysensors 54 and 48, respectively. Requiring door 18 to be open beforeswitch 24 is enabled prevents a foreign object being lodged between door18 and switch 24 from activating the surgical equipment upon closure ofdoor 18.

[0017] In a still further embodiment of the present invention, thesatellite switch 36 which is separate from, but electrically connectedto, the foot controller 32 may be enabled by sensors 48 and 54. In sucha configuration, satellite 36 is disabled except when the door 18 is inan open position. Or, in a redundant system, satellite 36 is disabledexcept when the door is present and in an open position. Such aconfiguration may be highly desirable when console 34 includes a lasercontrolled by switches 24 and/or 36, since the inadvertent operation ofswitch 24 or switch 36 could cause serious injury to the patient orothers in the operating room.

[0018] Various embodiments of an inventive surgical system 30 have beendescribed. The disablement of foot controller 32, switch 24, andsatellite switch 36 may be made from surgical console 34 with or withoutthe use of sensors 48 and 54.

[0019] It is noted that foot controller 32 is essentially identical tofoot controller 10 except that sensors 48 and 54 have been added.

[0020]FIG. 4 shows a block diagram of a circuit incorporatingcommercially available Hall-effect ICs 52 and 58. In addition toHall-effect IC 52, sensor 48 includes a switch 60 (in a preferredembodiment switches 60 and 64 combine to form switch 24) which isconnected to a relay 62. Switch 60 is typically electrically open andunpowered, unless Hall-effect IC 52 detects the presence of magnet 50,in which case switch 60 is powered and enabled. In an enabled state,switch 60 then controls relay 62. Relay 62 then sends an enabling signalto surgical console 34 causing the surgical instrument associated withswitch 24 to operate. If redundancy is desired, Hall-effect IC 58 thencooperates with Hall-effect IC 52 to enable or disable switch 24 and/or36.

[0021] Switch 64 and relay 66 provide redundancy for switch 60 and relay62. In a situation where switch 60 has failed in a powered and enabledposition, switch 64 and relay 66 ensure that the surgical instrumentattached to switch 24 will not be enabled accidentally. In a similarfashion, Hall-effect IC 58 prevents accidental operation because of thefailure of Hall-effect IC 52. Therefore, only IC 52, switch 64, andrelay 62 are needed for operation of the circuit of FIG. 4. IC 58,switch 64, and relay 66 provide a measure of safety redundancy.

We claim:
 1. A foot controller for use with ophthalmic surgery equipmentcomprising: a foot controller having a door; wherein the door is a coverfor a surgical switch when the door is in a closed position; wherein thedoor is a shroud for the surgical switch when the door is in an openposition; and a door-position sensor for disabling activation of thesurgical switch except when the door is in an open position.
 2. The footcontroller of claim 1 wherein the door position sensor is a Hall-effectsensor.
 3. The foot controller of claim 1 further including a satelliteswitch separate from but electrically connected to the foot controllersuch that the satellite switch is disabled except when the door is in anopen position.
 4. The foot controller of claim 3 wherein the surgicalswitch and the satellite switch control a surgical laser.
 5. The footcontroller of claim 1 further including a door presence sensor whereinthe surgical switch is disabled except when the door presence sensordetects the presence of the door and when the door position sensordetects the door in an open position.
 6. The foot controller of claim 5wherein the door presence sensor is a Hall-effect sensor.
 7. The footcontroller of claim 1 wherein the surgical switch controls a surgicallaser.
 8. A foot controller for use with ophthalmic surgery equipmentcomprising: a foot controller having a door; wherein the door is a coverfor a surgical switch when the door is in a closed position; wherein thedoor is a shroud for the surgical switch when the door is in an openposition; a satellite switch separate from but electrically connected tothe foot controller; a door position sensor for detecting when the dooris in an open position; a door presence sensor for detecting if the dooris present on the foot controller; and wherein the surgical switch andthe satellite switch are disabled except when the door is present andopen.
 9. The foot controller of claim 8 wherein the surgical switch andthe satellite switch control a surgical laser.
 10. The foot controllerof claim 8 wherein the door position sensor and the door presence sensorare each Hall-effect sensors.
 11. An ophthalmic surgical systemcomprising: a surgical console; a laser attached to and controlled bythe surgical console; a foot controller for activating various surgicalfunctions and instruments including the laser; wherein the footcontroller includes a laser switch for activating the laser; wherein thelaser switch is covered by a door; such that the door acts as a shroudwhen the door is in an open position; a door position sensor fordetecting when the door is in an open position; and wherein the laserswitch is disabled except when the door is in an open position.
 12. Thesystem of claim 11 further including a satellite switch for controllingthe laser separate from but electrically connected to the footcontroller such that the satellite switch is disabled except when thedoor is in an open position.
 13. The system of claim 11 furtherincluding: a door presence switch for detecting when the door is presenton the foot controller; and wherein the laser switch is disabled exceptwhen the door is both present and in an open position.
 14. The system ofclaim 13 wherein the door position sensor and the door-presence sensorare each a Hall-effect sensor.